JPH0631007B2 - Car body support structure - Google Patents

Description

The present invention relates to a vehicle body support structure, and more particularly, to a skeleton structure that defines an engine space, that is, a skeleton structure that constitutes an engine room and a floor portion of a vehicle body, a passenger space, and the like. The body and the body are respectively cast and molded, and by combining them to form a body frame integrally, it is possible to obtain a body frame having high rigidity and high precision, and at the same time, it is lightweight and has various shapes. The present invention relates to a vehicle body support structure capable of manufacturing a vehicle body.

For example, in order to reduce the fuel consumption of an automobile and enable long-distance running, it is required to reduce the weight of the vehicle body as much as possible. On the other hand, in order to protect an occupant from an impact due to a car accident or the like, it is desirable to construct the vehicle body with high rigidity, and the need for it is increasing more and more in recent years with the increase in speed of transportation means.

By the way, a body of a conventional automobile mainly employs a monocoque structure in which an exterior member such as a hood, a roof panel, and the like, which constitutes the vehicle body, and a vehicle body frame are integrated. This monocoque structure is assembled by joining each of the exterior members formed by press molding by welding or the like, and the cross-sectional shape of each of the formed exterior members is formed into a box shape having a role of a reinforcing rib. There is.

However, various difficulties have been pointed out in this monocoque structure in terms of weight saving and improvement of rigidity of the vehicle body.
That is, in order to reduce the weight of the vehicle body while maintaining the rigidity, for example, a steel plate having high rigidity and high tension must be used as an exterior member, and the steel plate must be thinned to reduce the weight. However, since such a steel plate has high rigidity, it is not suitable for ordinary press forming, and therefore it has not been easy to form the exterior member into a highly accurate shape. Further, if the outer member is made thin, its rigidity is naturally lowered. Therefore, in order to maintain the rigidity of the exterior member, the thickness of the exterior member is suppressed to a certain level or more, and as a result, it is not possible to expect a significant reduction in the weight of the vehicle body.

Therefore, in order to reduce the weight, a main part of the vehicle body is made of a steel plate having high rigidity, and a part that does not need strength to some extent, for example, a fender, a bonnet, etc. is made of a lightweight glass fiber reinforced plastic (hereinafter referred to as FRP), Alternatively, it may be configured with a synthetic resin material or the like. However, when assembling these exterior members, joining of the steel plate and FRP or the like becomes impossible, or the vehicle body is composed of a plurality of different materials, which may reduce the rigidity of the vehicle body.

Further, in such a monocoque structure, in order to manufacture the vehicle body with high accuracy, each exterior member must be accurately positioned by a special jig corresponding to its shape during assembly. Moreover, these jigs are required for each exterior member, and the equipment requires a great deal of expense.

Therefore, when many types of vehicle bodies having a monocoque structure are produced, a special jig is required for each exterior member of each vehicle body, and a complicated work process is required for the assembly. Therefore, such a monocoque structure is unsuitable for high-mix low-volume production of vehicle bodies, and there is a problem that it is not possible to promptly respond to changes in vehicle types.

Therefore, as a conventional technique for solving the above problem, a skeletal body frame is configured, and an exterior member made of a lightweight material is attached to the body frame, for example, in JP-A-60-135375. It is disclosed. That is, in this conventional technique, a tubular material formed by extrusion molding is assembled through a knotting member to form a skeleton-shaped vehicle body frame, and exterior members such as a door, a roof panel, and a hood are provided at predetermined portions of the vehicle body frame. I am trying to install it.

However, in the body frame configured in this way,
As described above, after connecting the respective pipe members by the respective knot members, it is necessary to perform welding or the like on the connection portions, and there is a disadvantage that a considerable time is required for the assembling work. Also,
The extreme thermal strain due to welding occurs at the connecting portion where the knot members are coupled, and the thermal strain is a major cause of lowering the rigidity of the vehicle body frame.

Further, each knot member needs to be selectively formed in various shapes such as one that connects two pipe members, one that connects three pipe members, or one that connects four pipe members,
Further, the length of the pipe material also differs depending on the location, and there is a drawback that a considerable working time, labor, cost, etc. are required for manufacturing these members. Moreover, in order to form the vehicle body frame with high precision, not only must each pipe member and the knot member be formed with high precision, but they must also be assembled with high precision, which requires a high level of skill and a great deal of working time. Is required. Therefore, it was not possible to expect a prompt response to changes in the vehicle type.

The present invention has been made in order to overcome the above-mentioned inconveniences, and casts a skeleton structure constituting an engine room and a floor portion of a vehicle body and a skeleton structure defining a passenger space and the like by light alloys, respectively. By providing them and combining them integrally, it is possible to obtain a highly rigid and highly accurate vehicle body frame, and to provide a vehicle body support structure that is extremely lightweight and that can easily produce vehicle bodies of various shapes. To aim.

In order to achieve the above object, the present invention provides a vehicle body support structure that supports exterior members such as a hood, a roof panel, side plates, and windows that form a vehicle body and defines an engine room, a passenger space, and the like. A first skeleton including a skeleton portion that includes the board front frame and defines the engine room, and a skeleton portion that includes a pair of protruding pieces that protrude upward from the rear wheel house frame and that constitutes a floor portion of the vehicle body. A structure, a front window outer peripheral frame that defines the riding space and surrounds the front window, a rear window outer peripheral frame that surrounds the rear window, and side center frames on both sides of the vehicle body are connected to form a loop. And a side loop frame that is The rear window outer peripheral frame or a portion in the vicinity thereof is coupled to the upper end portions of the pair of projecting pieces, and a part of the side loop frame is coupled to a skeleton portion constituting the floor portion. A second skeleton structure, wherein the first and second skeleton structures are respectively cast and formed by a light alloy, and the first and second skeleton structures are bonded and integrally formed. Characterize.

Preferred embodiments of the vehicle body support structure according to the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a vehicle body frame which is a vehicle body support structure according to the present invention, and the vehicle body frame 10 includes a first skeleton structure 12 which constitutes an engine room and a floor portion of the vehicle body, a passenger space, etc. Second skeletal structure that defines the
Basically composed of 14 and these first skeleton structures 12
The second skeleton structure 14 is integrally formed by casting an aluminum alloy, a magnesium alloy, or the like.

The first skeleton structure 12 is composed of a front part 13 that defines an engine room, and a floor part 15 that forms a bottom part of a passenger space and a rear part. The front part of the front part 13 is composed of bulkhead frames 18a to 18e, in which the bulkhead frames 18a and 18b are formed in parallel with each other, and the bulkhead frames 18a and 18b are arranged between the both ends and the middle part thereof.
They are connected by c to 18e. Further, one end of each of the front fender frames 20a and 20b extending toward the rear of the front part 13 is connected to both ends of the bulkhead frame 18a, and is connected between the other ends of the front fender frames 20a and 20b. Is connected to the dashboard front frame 21. The front portion 13 is provided near both ends of the bulkhead frame 18b.
Front lower frames 22a, 2 extending toward the rear of the vehicle
Each one end of 2b is connected. Then, between the middle part of the front fender frame 20a and the middle part of the front lower frame 22a, and between the middle part of the front fender frame 20b and the middle part of the front lower frame 22b, the vibration induced in the front part is controlled. Therefore, the front damper housing frames 24a and 24b are connected.

The other end portions of the front lower frames 22a and 22b are connected to the floor frame 26a. The floor frame 26a is arranged in parallel with the dashboard front frame 21, the side frames 28a and 28b are connected between the both ends of the dashboard front frame 21 and the floor frame 26a, and the center frame is provided between the middle portions. 30 are connected. Floor frame 26a
One end of each floor frame 32a, 32b extending toward the rear part of the vehicle body is connected to both ends of the floor frame, and between the floor frames 32a, 32b and between the other ends of the floor frames 32a, 32b. Floor frames 26b to 26d are connected in parallel with the floor frame 26a. In addition, these floor frames 2
A floor frame 34 connects the intermediate portions of 6a to 26d.

The floor frame 26d is connected to respective one ends of rear lower frames 36a and 36b extending toward the rear of the rear part, and the other ends of the rear lower frames 36a and 36b are connected to the rear frame 38. Further, one end of each of the rear wheel house frames 40a and 40b is connected to both ends of the floor frame 26d. And this rear wheel house frame 40a, 40b
The intermediate portions of the rear lower frames 36a and 36b are connected by rear damper housing frames 42a and 42b to reinforce the rear portions. Further, the rear wheel house frames 40a, 40b are formed with a pair of projecting pieces 43a, 43b projecting upward.

On the other hand, the second skeleton structure 14 has side frames 44a to 44c and 46a to 46c that form the periphery of the vehicle door, and the floor portion 15 of the first skeleton structure 12 is provided at an intermediate portion between the side frames 44b and 46b. The side center frames 48a and 48b extend in an oriented manner. A plate-shaped reinforcing frame 49 is connected between the end portions of the side center frames 48a and 48b. Further, both end portions of the side frames 44b and 46b and intermediate portions thereof are connected by roof frames 50a to 50c.
The ends of a and 46a are connected by a front center frame 51, and the ends of the side frames 44c and 46c are connected by a rear center frame 53. In addition, the side frame 44
Rear ends of the rear fender frames 55a and 55b are connected to respective ends of the c and 46c, and rear frames 59a and 59b are connected to the other ends of the rear fender frames 55a and 55b. A plate-shaped reinforcing frame 61 is connected between the ends of the rear frames 59a and 59b.

The side frames 44a and 46a, the roof frame 50a, and the front center frame 51 constitute a front window outer peripheral frame formed in a loop shape surrounding the front window. Also, the side frame 4
4c, 46c, roof frame 50c, and rear center frame 53 constitute a rear window outer peripheral frame formed in a loop shape surrounding the rear window. Further, the side center frames 48a and 48b, the reinforcing frame 49, and the roof frame 50b form a side loop frame formed in a loop shape.

Therefore, each frame constituting the body frame 10 is
For example, FIG. 2a, b, 3a, b or 4a,
It is formed as shown in b.

That is, the frame 52 shown in FIGS. 2A and 2B is formed to have an I-shaped cross section, and reinforcing ribs 52a and 52b are arranged at predetermined intervals. Further, in order to reduce the weight of the frame 52, a hole 52c is provided between the reinforcing ribs 52a and 52b. This frame 52
Is preferably used mainly for the bulkhead frames 18a to 18e, the rear fender frames 55a and 55b, the roof frames 50a to 50c, and the like.

Further, the frame 54 shown in FIGS. 3A and 3B has a U-shaped cross section, and reinforcing ribs 54a are arranged at predetermined intervals. A hole 54b for reducing the weight of the frame 54 is formed between the reinforcing ribs 54a. The frame 54 is appropriately selected in dimensions such as wall thickness, and for example, the front fender frames 20a, 20b, the front lower frames 22a, 22b, the dashboard front frame 21, the floor frame 34, the side frames 28a, 28b, 40a. , 40b, rear lower frame 36a, 36b
It is suitable to be used for the above.

The frame 56 shown in FIGS. 4a and 4b is formed in an E-shaped cross section and has reinforcing ribs 56a and 56b arranged at predetermined intervals.
It is heavier and has higher rigidity than the frame 54 shown in FIGS. A and b, and is suitable for use in, for example, a main part of the floor frame 34 or the like. Here, as a matter of course, it is possible to use a frame having a shape other than the above in consideration of the load condition of each part.

The vehicle body support structure according to the present invention is basically constructed as described above. Next, its operation and effect will be described.

As a method of integrally casting the first and second skeleton structures 12 and 14, respectively, for example, it is suitable to use an investment casting method which is a typical precision casting method. That is, in this casting method, first, a mold model in which the structures 12 and 14 are disassembled into main constituent parts is manufactured. Next, after the respective parts of the structures 12, 14 made of, for example, foamed plastic are molded by the mold model, the respective parts of the structures 12, 14 are assembled by assembling the respective parts. The master thus constructed is dipped in a sandy slurry or the like which constitutes the mold to coat the surface of the master. After the slurry or the like attached to the surface of the master mold is dried and solidified, molding sand is pressed against the periphery of the master mold to form a sand mold.
Then, the molten aluminum alloy is injected through a predetermined runner formed in the sand mold. In this case, the plastic foam is melted by the aluminum alloy and the prototype is replaced by the aluminum alloy. as a result,
The first and second aluminum alloys shown in FIG.
The skeletal structures 12 and 14 are integrally cast in a sand mold. At that time, it is preferable to integrally form a bracket, a stay or the like for mounting the exterior member at the time of molding on each of the structures 12 and 14 that have been molded by casting. Of course, the body frame 10 may be formed by casting a magnesium alloy instead of the aluminum alloy.

Next, the cast-molded structures 12 and 14 are subjected to an annealing treatment or a solution treatment.

That is, when the structures 12 and 14 are annealed, for example, each of the structures 12 and 14 is heated to 200 ° C. to 250 ° C., and the state is held for 5 to 10 hours, and then, the air is removed by air. Cool slowly.

In this case, in each of the annealed structures 12 and 14, the thermal strain generated during casting is removed, and a highly accurate shape is obtained. Further, the strain with time is not exposed, and the structures 12 and 14 having stable properties are obtained.

On the other hand, when the solution treatment is performed on the structures 12 and 14, for example, each structure 12 and 14 is heated to 500 to 530 ° C., and the state is maintained for 5 to 10 hours, and then rapidly cooled with cooling water. Cool and quench. Next, after heating to 150 ° C. to 180 and maintaining this state for 5 to 15 hours, it is gradually cooled by air to age-harden the structures 12 and 14.

In this case, the structures 12, 14 artificially age-hardened after the solution treatment show extremely high rigidity, and
The properties of 12 and 14 are stabilized.

The structures 12 and 14 thus annealed or solution treated are blown away from the foundry sand adhering to the surface by shot blasting, degreased by alkali cleaning, and sprayed with an epoxy resin to prevent rusting. The coating process is applied. Next, a mounting hole for mounting each exterior member is formed by machining on a bracket, a stay or the like integrally formed with the structures 12 and 14.

First and second skeleton structures formed as described above
12 and 14 have predetermined sites bound to each other.

That is, the front center frame of the second skeleton structure 14
51 is the front frame 21 of the dashboard of the first skeletal structure 12.
Are joined to and joined by bolts. In addition, each end of the side center frames 48a and 48b and the reinforcing frame 49
The intermediate portions of are connected to the intermediate portions of the floor frames 32a, 32b and 34 by bolts or the like, respectively. Both end portions of the rear center frame 53 are rear wheel house frames 40a, 4
0b from the upper portion of the projecting pieces 43a, 43b projecting to the upper portion is connected by a bolt or the like. Further, the respective end portions of the rear frames 59a and 59b and the reinforcing frame 61 are joined to the rear frame 38 and joined by bolts or the like. In this way, the vehicle body frame 10 is connected and integrally configured as shown in FIG.

Here, since each structure 12, 14 is integrally formed by casting, it is not necessary to connect each frame constituting the structure 12, 14 by welding or the like, and the assembling work thereof is not necessary. There is no fear that the structural bodies 12 and 14 will be weakened due to the local thermal strain generated by. Further, since the first skeleton structure 12 integrally forms the engine room and the floor portion of the vehicle body, the rigidity of the vehicle body is maintained well. Therefore, the vehicle body frame 10 composed of such structures 12 and 14 has extremely high rigidity, and the dimensions thereof are extremely highly accurate. Furthermore, this body frame 10 is the first
And the second skeleton structures 12 and 14 are respectively molded in a divided state, so that the skeleton structures 12 and 14 can be easily manufactured without requiring a relatively large mold during casting. I can.

The exterior members shown in FIG. 5 are attached to the vehicle body frame 10 manufactured by the above steps. That is, the bumper 58 is attached to the bulkhead frames 18a to 18e in the front portion 13, and the front fender frame is
Front wheel arch 60 surrounding the front wheels on 20a and 20b
The front fender 62 is attached, and the floor panel 64 is attached between the front lower frames 22a and 22b. A bonnet 66 is attached to a portion surrounded by the front fender frames 20a and 20b, the bulkhead frame 18a and the dashboard front frame 21. Similarly, the side frames 44a to 4a of the second skeleton structure 14
4c, 46a to 46c, 28a, 28b, rear wheel house frames 40a, 40b and side center frames 48a, 48b have front doors 68 and rear doors 70 attached thereto, and roof frames 50a to 50c have roof panels 72 attached thereto. To be done. A rear fender 74 is attached to the rear fender frames 55a and 55b, and a trunk lid 76 is attached between the rear fender frames 55a and 55b. Further, a rear floor panel 78 is attached to the rear lower frames 36a and 36b. In addition, although not shown, an instrument panel, a suspension, and the like are attached to the vehicle body frame 10 as necessary to form a vehicle body.

Here, since the body frame 10 is formed extremely accurately, the exterior member can be assembled with high precision.
Moreover, since it is not necessary to position these exterior members by special jigs at the time of assembling, the exterior members can be easily and inexpensively assembled.

Further, the body frame 10 includes the first and second skeleton structures 12,
By 14, the sedan type shown in FIG. 5 is formed. Therefore, for example, as shown in FIG.
The first skeleton structure 12 and the new second common to the case of the sedan type
If configured with the skeleton structure 80, the vehicle body frame 10 can be changed to a hatchback type vehicle body frame 82. In this case, no special jig is required for attaching the exterior member to the second skeleton structure 80, as in the case of the sedan type. Therefore, it is possible to change the vehicle type very easily and inexpensively.

Further, unlike the case of the monocoque structure, the vehicle body having the vehicle body frame 10 or 82 as a skeleton does not require any considerable strength for the exterior member. Therefore, FR is used as the exterior member.
Light-weight materials such as P, synthetic resin, and aluminum can be used, and the weight of the entire vehicle body is reduced. Further, if the exterior member is formed by using FRP or the like that is colored in advance, it is possible to reduce the number of vehicle body painting steps. Moreover, in the same body frame 10 or 82, it is possible to easily change the color, outer shape, design, etc. of the exterior member, so that it is possible to manufacture various vehicle bodies at low cost.

As described above, according to the present invention, the first skeleton structure that constitutes the engine room and the floor portion of the vehicle body and the second skeleton structure that defines the passenger space and the like are cast and formed from light alloys, respectively, and these are formed. The body frame is configured by being integrally connected. In this case, since the outer peripheral portion of the front window, the outer peripheral portion of the rear window, and the side center frame portion are each formed of a loop-shaped frame, sufficient rigidity of the second skeleton structure itself should be ensured. You can When the second skeleton structure is joined to the first skeleton structure, the dashboard front frame of the first skeleton structure and a part of the front window outer frame of the second skeleton structure are joined. As a result, the rigidity of the front portion of the vehicle body is further improved, and the protruding piece of the first skeletal structure is coupled to the rear window outer peripheral frame of the second skeletal structure or in the vicinity thereof, and is independent of the rear window outer peripheral frame. Since the loop-shaped frame structure is formed in the rear part, the rigidity of the rear part of the vehicle body is also improved. Therefore, it is possible to make the entire vehicle body highly rigid and lightweight. Further, since the body frame is integrally formed, the precision thereof is extremely high, and the exterior member can be assembled to the body frame with high precision. Further, since the vehicle type can be easily changed only by exchanging the first or second skeleton structure, there is an advantage that it is possible to easily realize high-mix low-volume production of vehicle bodies.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the scope of the present invention. Of course.

[Brief description of drawings]

1 is an exploded perspective view showing a vehicle body support structure according to the present invention, FIGS. 2a and 2b are a sectional view and a partial side view of a frame used in the vehicle body support structure according to the present invention, and FIG. 3a and FIG. b is a sectional view and a partial side view of another frame used for the vehicle body support structure according to the present invention, and FIGS. 4A and 4B are sectional views of still another frame used for the vehicle body support structure according to the present invention. FIG. 5 is a partial side view, FIG. 5 is a partially exploded perspective view showing a vehicle body support structure and an exterior member thereof according to the present invention, and FIG. 6 is an exploded configuration diagram showing another embodiment of the vehicle body support structure according to the present invention. is there. 10 …… Body frame, 12 …… Skeletal structure 13 …… Front part, 14 …… Skeletal structure 15 …… Floor part, 52, 54, 56 …… Frame 80 …… Skeletal structure, 82 …… Body frame

Claims (1)

[Claims] 1. A vehicle body support structure for supporting exterior members such as a bonnet, a roof panel, side plates, and windows that form a vehicle body and defining an engine room, a passenger space, and the like, including a dashboard front frame, A first skeleton structure including a skeleton portion that defines an engine room, a skeleton portion that includes a pair of projecting pieces that protrude upward from a rear wheel house frame, and that constitutes a floor portion of a vehicle body, the riding space, etc. And includes a front window outer peripheral frame that surrounds the front window, a rear window outer peripheral frame that surrounds the rear window, and a side loop frame that forms a loop by connecting side center frames on both sides of the vehicle body, A part of the front window outer frame is joined along the dashboard front frame. A second skeleton structure in which the rear window outer peripheral frame or a portion in the vicinity thereof is coupled to upper ends of the pair of projecting pieces, and a part of the side loop frame is coupled to a skeleton constituting the floor portion; A vehicle body support structure, characterized in that the first and second skeleton structures are respectively cast-molded with a light alloy, and the first and second skeleton structures are joined and integrally formed. .